Researchers To Predict Spread Of 'Super-Bug' In LA Jail

Armen Hareyan's picture

Methicillin-Resistant Staphylococcus Aureus

Researchers have developed a mathematical model that mimics a particularly nasty and ongoing outbreak at the Los Angeles County Jail of the flesh-eating bacteria known as methicillin-resistant Staphylococcus aureus, or MRSA.

Reporting in the September issue of Nature Reviews Microbiology (currently online), Sally Blower, a professor of biomathematics at the Semel Institute for Neuroscience and Human Behavior at UCLA, and colleagues constructed a simple model of the outbreak in order to assess its severity, predict the consequences of a catastrophic outbreak and suggest effective interventions to stop or control it.


Blower was intrigued by the outbreak at the jail of a form of MRSA called community-acquired methicillin-resistant S. aureus (CA-MRSA), a "super-bug" that is difficult to eradicate and that spreads easily under crowded conditions with less than optimal hygiene. In infected individuals, the bug can cause symptoms ranging from minor skin infections to severe skin ulcers, and in some cases life-threatening diseases.

Incarceration has been identified as a major risk factor for CA-MRSA infection. While large outbreaks have been reported in jails around the country, the researchers chose the Los Angeles County Jail for two reasons: It is the nation's largest jail, housing some 165,000 inmates a year and approximately 20,000 at any given time, and it has a high rate of CA-MRSA infection. An outbreak was first reported in 2002, and it continues to this day.

To date, nearly 8,500 cases have been reported at the jail, and, said Blower, "inmates, once they are released, are spreading the pathogen throughout the community as well."

With cooperation from jail officials, the researchers compiled information that determined booking rates (inflow), duration of jail stay (outflow), the rate of CA-MRSA transmission within the jail and the prisoners' status with regard to CA-MRSA infection